When Everyone Knows That Everyone KnowsWhen Everyone Knows That Everyone Knows

Common knowledge is essential for coordination, enabling people to make complementary choices such as following traffic rules, using currency, and rallying behind political movements. It also plays a crucial role in social interactions, from speaking the same language to building relationships. Humans have an innate ability to create common knowledge through signals like laughter, eye contact, and direct speech. However, people often go to great lengths to avoid common knowledge, using rituals like hypocrisy, veiled threats, and pretending to ignore obvious truths. Steven Pinker explores how the hidden mechanics of common knowledge explain various social phenomena, including financial crises, sudden revolutions, diplomatic maneuvering, social media outrage, and the awkwardness of dating. Artists and humorists have long captured these dynamics in literature, film, and comedy, which Pinker draws upon to illustrate his points. He delves into questions such as why people hoard supplies in crises, why Super Bowl ads promote cryptocurrency, why voters choose candidates based on perceived popularity, why Russian authorities arrest protesters with blank signs, and why complete honesty would make life unbearable. Through these examples, he reveals the complexities of what we all know₇and what we try to pretend we don₂t.